Robert Lewis Letsinger (July 31, 1921 – May 26, 2014) was an American biochemist and was a professor of chemistry at Northwestern University.
He retired from teaching in 1991 as the emeritus Clare Hamilton Hall Professor.
In the 1960s, Letsinger developed methods for solid phase synthesis of oligonucleotides, including the phosphoric triester method[2] and the phosphoramidite synthesis.
He thus laid the foundations for efficient automated synthesis of gene fragments and thus the rapid development of molecular biology.
[3] Letsingers later dealt with nanotechnology and its application in DNA diagnostics.